Enclosures are commonly used to provide a degree of protection to personnel against incidental contact with enclosed equipment and to provide a degree of protection against the surrounding environment for enclosed equipment. Typical enclosures include a box and a door sealed thereto. Frequent access to the components within such enclosures is common for adjustments, maintenance, and inspection of the components. Components within the enclosure may also be changed or replaced as the demand therefor changes. Typically, the components are fastened to a panel inside the enclosure. Panels and components must typically be dismounted from the interior of the enclosure and replaced by other components. Further, enclosures are often used to house many different electronic and/or electric components and their associated wiring and control circuitry. These components, their associated wiring, and the panels all come in varying shapes and sizes. Still further, the components must be fastened in place and often several different components must be mounted rigidly in the same housing and/or in a fixed spatial relationship. Therefore flexibility in component placement is important.
Oftentimes, the total production run of any one particular combination of components is somewhat limited and the cost of producing a custom enclosure is not economically justified. In such instances, enclosures having an ability to be adapted to different component mounting arrangements are used. Similarly, when performing field installation of various electrical wiring and control systems, it is often necessary to install many different combinations of components. In order to maintain the number of different enclosures required to a reasonable level, it is desirable to have enclosures which are extremely flexible in that they are able to accommodate a wide variety of components and mounting arrangements.
Some prior art enclosures include means to accommodate multiple components and mounting arrangements yet suffer from a number of drawbacks. For example, an enclosure in the shape of a box may include one or more tracks which extend from the bottom to the top of the enclosure. Mounting brackets which hold electrical components or the like may be slid to and fro along the track until a desired position is attained. A tool may then be inserted through a front face of the enclosure to access one or more fasteners positioned at right angles to the side walls of the enclosure and which, when tightened, engage the side wall to secure the bracket to the track.
Another undesirable aspect of such mounting structure is that the fastener engages the side wall behind the track. The side wall usually consists of a relatively flat panel structure and the force exerted thereon by the fastener is a point or concentrated source at right angles. Consequently, the fastener, when engaging the respective side wall, affects, at least partially, the structural integrity of the side wall, especially over time whereby components may be repeatedly repositioned, requiring the fasteners to be repeatedly repositioned and retightened into the side wall. In addition, the structure may be relatively flimsy, even without this added problem, when exposed to forces in certain directions. Therefore, it is desirable to increase the strength or rigidity of the enclosures. Of course, the thickness of the side walls may be increased to better withstand the effects of the engaging fasteners, but this increased thickness results in higher material and manufacturing costs.